Hydraulic tube beader



Aug. 17, 1943. o. 1... WOODSON 2,326,990

HYDRAULIC TUBE BEADER Filed Apri1.l4, 1942 2 Sheets-Sheet l INVENTOR OmerLWoodson,

' ATTORNEYS Aug. 17,1943. q 1.. WOODSQNY 2,326,990 I HYDRAULIC TUBE BEADER Filed April 14, 1942 2 Sheets-Sheet 2 Fig.2.

IIII/I/IIII lI/IIIIII/I/ INVENTOR OmagLWoodson,

ATT RNEYS Patented Aug. 17, 1943 Omen L. Woodson, Eggertsville, N. Y., assignor to Bell Aircraft. CorporatiomBulfalo, N. Y. 7

ap licatio April" 14, 1942, Serial No. 438,913

This invention relates to fluid" means, ferroming sheet metal; and is shown, herein as comprising novel'hydraulic fluid means for forming an embossed bead upon a tube of metal or the like but it will be understood that thepri-nciples of the invention may be employed in other analagous manufacturing operations. I

According to the present invention there are 01" mold Thus, the possibility that the hydraulic metal deforming force acting within'the work piece deforming chamber may separate the die elements while performing the metal forming operation is entirelyelirninated; In the; embodiment which is: set forth herein by way of example, mechanical means are proelement +2; The die element ['2 is attached; to the wall portion H by means of a dove-tail joint or the like as indicated at l3.

A second relatively movable die element is designated i4 and is likewise attached by means of a dove-tail joint l5 to a reciprocable die holder 16. By means of the dove-tail joints I 3 and I5, the die elements 12 and I4 may be readily removed from assembly with the wall portion H and the die holder ii for substitution of dies when working upon work pieces of other sizes or other desired conformation. e

The opposed faces of the die elements l2 and 14 have complementarysemi-circular depressions whereby to receive and hold a work piece in the form of amine l1 when'the die elements are'in abutment with eachother. It is desired to dispose a mandrel designated generally l-8- within vided for major movements ofthe'. die elements between open and closed position. In this way arrangement is made whereby the applicationgoi hydraulic force within the die chamber and upon the hydraulic force holding mechanism fDrkeeping the separable die "elements in closed forming position may be effected simultaneously and by use of a single valve. The apparatus of the invention is simple and economical in construction and extremely facile in use. Other objects and advantages attended upon a pursuance of the principles underlying the invention will an pear from a consideration of the particular embodiment set forth herein by way of example.

In the drawings:

Fig. 1* is atop plan viewof oneformer the apparatus;

Figb2 is a cross sectiona'l view takenas cated by the line 11-11, Fig. 1; and V 7 Fig. 3 is a cross sectional view on an enlarged scale taken on the'line II'IIH of Fig. 1.

Throughout the several figures of the drawings like characters of reference-denote like partsand. the numeral Hi designates base meansinthe form of a plate, or the like, having formed rigidly therewith an extending wall portion If for attachment thereto or a relativelyimnroyabie die the work piece H and means are accordingly provided for supporting the mandrel I 8 in a central position with respect to the die elements I2- and it For ready disposition of a workpiece I! over the mandrel l8 it is further desired that the mandrel l8be disposedcentrally between the die elements i2 and M when the latter are in open or separated position, and to this end the mandrel I8 is supported in a manner which will now be described.

A mandrel-supporting plate is designated 20 and has a central opening for supporting the mandrel 18 in fixed relation with respect thereto. The plate 20 is formed with elongate-slots 2| and 22,-and corresponding screws 23 and 24 pass through the slots and threadedly engage the side Walls of the die elements l4 and I2 respectively. The slots 2| and22 are soformed and arranged (Fig. 2) that upon relativeopening movement of the die element I 4 with respect to the die element 12 to a distance approximately equal to the sum of the lengths of the slots 2| and 22 the mandrel 18 will be automatically disposed centrally with respect to the dieelements; and in such condition of the apparatus the screws 2-3 and 24 will be engaged against the outer endsof the slots 2| and 22, respectively. Inthe illustrated instance the die elements l2- and I4 are provided with longitudinal recesses for receiving and guiding the plate 20. v

It willbe noted that the semi-circular depressions in the die elements and H are provided for receiving and holding the work piece l1 while forming enlargements therein as indicated at 21. Fo this purposethe dies are recessed as shown for receiving a portion'of the tube which is expanded by operation of the mandrel L'B-for the purpose of forming an encircling bead on the tubular work piece IT. The mandrel has heretofore been generally designated l8 and comprises more specifically a cylindrical body element 30 which has disposed thereabout a resilient sleeve 3| which may be of rubber or the like but is preferably of a suitable oil resisting synthetic rubber such as Neoprene or the like. The body element 30 is threaded at opposite ends of the resilient sleeve 31 to receive glandular retaining elements 32 and 33 which confine the flexible sleeve 3| axially. The outer end of the glandular element; 33 may be rounded as at 34 to facilitate disposition of the tubular work piece I1 over the mandrel.

Ihe body element 30 of the mandrel has an axial fluid passage 31 which emerges from the left hand end of the body element as as viewed in Fig. 3 in an extension 38 formed at its end of the; body element. At its right hand end the iiuid passage 3'! terminates in the vicinity of the beading enlargement in the semi-circular die openings. .At its terminus the passage 2? has a radial extension 46 emerging at the periphery of the bodyelement 30 whereby a hydraulic mebe directed under pressure against the inner periphery of the resilient sleeve 3! to deform the latter outwardly as illustrated in Fig. 3 to produce the annular bead fir he tu ular work piece at 21 as shown in that n ire. since the threaded opening in the glandular element 32 extends wholly therethrough, it is desirable to seal the outer end thereof against fluid leakage and accordingly the end of the gland shaped to be inwardly conical and an annular element 42 is pressed thereagainst and secured position by means of a nut 43. A supporting sleeve is disposed securely about a portion of the gland element 322 and, in

the present instance, about a portion of the resilient sleeve 31. The supporting sleeve 45 has an outwardiy directed annular flange 46 which is preferably secured directly and ri 'idly to the supporting plate 26, whereby central positioning of the mandrel assembly with respect to the elements 12 and M is assured inboth open and closed positions of the apparatus. The outer end of the extension 38 of the body element 39 of the mandrel is threaded to receive a nipple 50 which is associated with a hydraulic conduit 5|.

Means for closing and opening the die apparatus preliminary and subsequent to the beading operation upon the work piece, as istinguished from the hydraulic die holding means which will subsequently be described, is shown as comprising a casing which supports for longitudinal sliding movement a bar 56 which is rigidly associated with the die holder IS in any conventional manner. In the present instance the bar 56 is shown as having a slotted outer end for receiving a fiatted head 57 of a screw 58 which threadedly engages the die holder iii. A set screw or the like as at 59 is employed to secure the fiatted head 51 to the bar 56. f

The bar 55 is provided with a further slotted portion whose ends are designated fil and 62 respectiveiy in Fig. Land a flat cam 53 is disposed in this slot and is fixed to a carrying *shaftG-t jcurnaled in the casing 55. The bar 55 has a longitudinal slot 65 for receiving theshaft 64 to permit longitudinal movement of the bar 56 with respect to the shaft 64. Obviously, as viewed in Fig. 1, rotation of the shaft 64 and the cam 63 through approximately 180 will move the bar 5'6 to a position where the movable die clement I4 is substantially separated from the stationary die element I2. Upon such movement the mandrel is automatically disposed approximately midway in the open space between the two die elements, as has heretofore been explained. Manipulation of the cam 63 by means of the rock shaft 64 for opening and closing the die apparatus is effected simply by the provision of a manual operating crank or handle indicated at 61.

For assuring maintenance of the separable die element in tightly closed condition during the heading operation a pair of hydraulic rams having operating cylinders 1e and projecting plungers H are provided. The cylinders 10 are secured to the base I!) in such manner as to direct the plungers ll against the outside of the die holder l6 in such manner as to urge the die 14 against the stationary die element l2 when hydraulic pressure is applied to the cylinders "Hi. In Fig. .1, a hydraulic pressure supply line designated leads to one of the cylinders 19 and is provided with a branch conduit '16 leading to the other of the'cylinders 70. A second branch of the supply conduit 15 constitutes the previously described conduit 5| for supplying fluid pressure within the resilient sleeve 3|.

The effective fluid pressure responsive total area of the heads of the plungers ll within the cylinders I0 is arranged to be such that the total force holding the die elements l2 and M in closed position is, under any fluid pressure condition, materially greater than any force generated Within the mandrel tending to separate the die elements. Therefore, by virtue of this arrangement not even the slightest separation of the die elements during the tube expanding operation is permitted, either as a result of play in the clamp ing, means or of a preponderant expanding force within the'mandr'el. Thus, the objectionable features of prior art devices of this type are avoided, and inaccuracies in the final product and/ or production of fins thereon due to die separation are absolutely prevented.

Although only one form of the invention has been shown and described in detail, it will be apparent to those skilled in the art. that the inventionis not so limited but that various changes may be made without departing from the spirit of the invention or the scope of the appended claims.

. I claim:v

1. Tube forming apparatus comprising a pair of complementary tube encircling elements movable toward and away from each other, mandrel means between said tube encircling elements for disposition within a tubular work piece, said mandrel means comprising a flexible sleeve whereby hydraulic pressure within said mandrel urges said sleeve against the tube encircling elements to form the tubular work piece in conformity with the tube engaging surfaces of the tube encircling elements, and hydraulic means for urging said tube encircling element against said tubular work piece, said hydraulic means being proportioned to exert a greater tube encircling force than the tube forming force within said mandrel, and means engaging said encircling elements and adapted to support said mandrel means therebetween, said supporting means being operative to dispose said mandrel means substantially midway between said encircling elements when the latter are in spaced, open position.

. 2. Metal forming apparatus comprising a pair of complementary mold-forming elements mov- 3. Metal forming apparatus comprising a pair of complementary mold-forming elements, means comprising a core within said mold, said core having a flexible wall portion and hydraulic means for expanding said wall portion, one of said mold-forming elements being movable to expose said core for disposing a work piece thereagainst, a lost motion connection between said movable mold-forming element and said core whereby opening movement of said element removes it from said core and likewise automatically removes the latter from the other moldformlng element, said hydraulic means being arranged to bear against one of said mold-forming elements when said flexible wall portion is being hydraulically expanded to urge the mold-forming elements toward each other. i

4. Metal forming apparatus comprising rigid diemeans and a hydraulically expansible jacket for urging metal into conformity with said rigid die, and means whereby the hydraulic medium of said jacket is simultaneously directed against said rigid die means to urge same into forcible engagement with said jacket, a portion of said rigid die means being movable with respect to the remainder thereof to expose said jacket and permit the introduction and removal of work pieces, a lost motion connection between the movable portion of said die means and said expansible jacket whereby movement of said portion to expose said jacket automatically moves said jacket out o! the remaining portion of said die means, said hydraulic means being proportioned to direct a greater force for maintaining said die means and said jacket in operative engagement than the force exerted by said jacket tending to displace the latter relative to said die means.

OMER L. WOODSON. 

